The bratty adolescent protagonist, as long as the anime does a good job as a coming-of-age story. It's always nice to compare a character from their whiny/weak self in episode one to their developed, mature self at the end.

For me I have always wanted to see an Anime that takes place in a prison (if there is one out there I apologize)
do kind of a Shawshank Redemption kind of thing. Why not? If we can have anime's about working in a goddamn restaurant we can have a character driven Prison Anime.

I never tire of the servant x master animes, especially those with a younger male protagonist and an older male protector. Examples include PandoraHearts, Makai Ouji, Kuroshitsuji, and Hakkenden.
I also love slice of life anime centered around a group of male friends (like Free!).

I just want to make it clear that I don't prefer the cast to be mostly male because of some yaoi or shipping fantasy. I just think males make for better stories.

I want to see more ass kicking demon girls somehow being together with totally powerless humans and wondering why the people are scared if her eyes glow at them even if she just is a bit angry and not yet killing angry